Electronic sphygmomanometer and blood pressure measurement method

ABSTRACT

An electronic sphygmomanometer includes a cuff to be attached to a blood pressure measurement site, a pump and a valve for adjusting a pressure to apply to the cuff, a pressure sensor for detecting a pressure of the cuff, a central processing unit (CPU) for calculating a blood pressure value from the cuff pressure, a memory for recording the blood pressure value, and an operation unit for carrying out a blood pressure measurement. The CPU corrects the calculated blood pressure value based on separately acquired correction information and acquires attachment condition information of the cuff as the correction information. When the attachment condition information is acquired as the correction information, the CPU corrects a blood pressure calculation parameter based on the attachment condition information.

CROSS REFERENCE TO RELATED APPLICATION

This application, pursuant to 35 U.S.C. §120, claims benefit to and is a continuation of PCT International Application Number PCT/JP2009/007288, filed Dec. 25, 2009 which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to an electronic sphygmomanometer including a cuff to be attached to a blood pressure measurement site and a blood pressure calculation unit for calculating a blood pressure value from a cuff pressure, and a blood pressure measuring method using the same.

BACKGROUND ART

A blood pressure is one type of index for analyzing a circulatory disease. Performing risk analysis based on the blood pressure is effective in preventing cardiovascular related disease such as apoplexy, cardiac arrest, and cardiac infarction. Conventionally, a diagnosis for performing the risk analysis is made from the blood pressure (occasional blood pressure) measured in medical institutions at the time of hospital visits and checkups. However, it is recognized from recent research that the blood pressure (home blood pressure) measured at home is more useful in diagnosing the circulatory disease than the occasional blood pressure. Accompanied therewith, the sphygmomanometer used at home is being widely used.

Most of the electronic sphygmomanometers currently being widely used use a blood pressure calculation algorithm of an oscillometric method. In the oscillometric method, a cuff is wrapped around a measurement site such as an upper arm and pressurized up to a predetermined pressure, and then depressurized gradually or in a step-wise manner. The oscillometric method is a method of detecting a change in arterial volume that occurs in the middle of depressurization as a pressure change (pressure pulse wave amplitude) superimposed on the cuff pressure, and applying a predetermined algorithm on the change in the pressure pulse wave amplitude to determine the systolic blood pressure and the diastolic blood pressure. Generally, a point where the pressure pulse wave amplitude suddenly becomes large obtained during the depressurization is approximated as the systolic blood pressure, and a point where the pressure pulse wave amplitude suddenly becomes small is approximated as the diastolic blood pressure. Various algorithms have been reviewed to detect such points.

For instance, as shown in FIG. 18 and [Equation 1] below, it has been proposed that a value obtained by multiplying a predetermined ratio to a maximum value of the pressure pulse wave amplitude is set as a blood pressure calculation parameter, and the cuff pressure at which the pressure pulse wave amplitude that matches (or is closest to) the relevant parameter is obtained and is calculated as the blood pressure value (see patent document 1).

Systolic blood pressure calculation parameter=maximum value of pressure pulse wave amplitude×α

Diastolic blood pressure calculation parameter=maximum value of pressure pulse wave amplitude×β  [Equation 1]

Patent Document 1: Japanese Unexamined Patent Publication No. 3-81375

SUMMARY OF INVENTION

However, there is no theoretical evidence that the point where the pressure pulse wave amplitude suddenly changes matches the systolic blood pressure and the diastolic blood pressure. Thus, the ratios (α, β) for determining the blood pressure calculation parameter had to be experimentally or statistically determined based on the change pattern (hereinafter referred to as “envelope curve”) of a great number of blood pressure values and pressure pulse wave amplitudes.

The blood pressure of a pregnant woman or a child (e.g., 18 years old or younger) has properties of being different from a general adult. In the ausculatory method in which the medical staff carries out the blood pressure measurement, the diastolic blood pressure is determined at a point where the Korotkoff sound (hereinafter referred to as K sound) disappears while depressurizing the cuff pressure.

Pregnant women and children, however, have properties in that the K sound continues to be heard even if the cuff pressure becomes around 0 mmHg, and hence, if the disappearing point of the K sound is assumed as the diastolic blood pressure, this becomes a very low value.

In the case of pregnant women and children, the point where the K sound changes in the middle of depressurization is determined as the diastolic blood pressure (Method for measuring blood pressure and clinical evaluation: Tochikubo Osamu; Medical Tribune; 1998: P. 13 and P. 24).

Accordingly, the measurement value sometimes contains error even if the blood pressure is calculated through the oscillometric method if the blood pressure is calculated at a characteristic point in the envelope curve of a general adult.

Furthermore, the type (size) of the cuff normally needs to be changed according to the peripheral length of the measurement site to appropriately compress the artery of the measurement site, but the shape of the envelope curve differs depending on the type of the cuff. This is because the pressure pulse wave amplitude that forms the envelope curve is such that the air volume change of the cuff generated by the arterial volume change is detected as the pressure change superimposed on the cuff pressure, and the pressure pulse wave amplitude detected by the size (air volume in the cuff) of the cuff differs even if the same arterial volume change occurs.

The phenomenon in which the pressure pulse wave amplitude detected by the cuff differs also occurs by material, thickness, hardness, or the like other than the size of the cuff. Therefore, the blood pressure calculation parameter differs depending on the cuff even if the subject is the same.

Accordingly, the measurement value sometimes contains error according to the cuff when calculating the blood pressure with the oscillometric method.

A method of determining the size of the cuff to be attached, and controlling the air supply amount to the cuff according to the size of the cuff (Japanese Unexamined Patent Publication No. 2-307427) is a conventional technology, but the measurement accuracy is poor because the same blood pressure calculation algorithm is used at the time of the measurement.

The shape of the envelope curve differs depending on the measurement site. The site to measure the home blood pressure is generally the upper arm, the wrist, or the finger. The upper arm, the wrist, and the finger have different physiological structures such as the peripheral tissue of the artery (thickness of muscle, position of bone, position of tendon, etc.), the thickness of the artery (upper arm is generally thicker), the number of arteries (two arteries, radial artery and ulnar artery are traveling in the wrist), and the like.

The shape of the envelope curve to be detected thus differs among the upper arm, the wrist, and the finger. Therefore, the blood pressure calculation parameter differs depending on the measurement site.

Accordingly, the measurement value sometimes contains error depending on the measurement site when calculating the blood pressure with the oscillometric method.

Therefore, one or more embodiments of the present invention provides an electronic sphygmomanometer and a blood pressure measurement method for accurately acquiring a blood pressure value using acquired data by correcting a blood pressure calculation parameter based on attachment condition information of the cuff, and enhancing the satisfaction level of the user.

According to one or more embodiments of the present invention, an electronic sphygmomanometer includes a cuff to be attached to a blood pressure measurement site, a pressurization and depressurization means for adjusting pressure to apply to the cuff, a pressure detection means for detecting pressure of the cuff, a blood pressure calculation means for calculating a blood pressure value from the cuff pressure, a recording means for recording the blood pressure value, and an operation means for carrying out operation such as blood pressure measurement; the electronic sphygmomanometer including a correction means for correcting a blood pressure value calculated by the blood pressure calculation means based on separately acquired correction information; and an information acquiring means for acquiring attachment condition information of the cuff as the correction information; wherein when the attachment condition information is acquired as the correction information by the information acquiring means, the correction means corrects a blood pressure calculation parameter based on the attachment condition information; and the attachment condition information is user information input for specifying user indicating properties different from a general adult.

According to one or more embodiments of the present invention, the optimum blood pressure calculation parameter can be set for every attachment condition according to the attachment condition information and the measurement error can be reduced even if properties are different for every attachment condition of the cuff.

Further, according to one or more embodiments of the invention, the attachment condition information is configured by user information input before start of the blood pressure measurement.

According to one or more embodiments of the present invention, the optimum blood pressure calculation parameter can be set for every user according to the information of the user and the measurement error can be reduced even if properties are different for every user.

Further, according to one or more embodiments of the invention, the user information is configured by at least one of information such as a child or a pregnant woman, age, and birth date.

Further, according to one or more embodiments of the invention, the attachment condition information is configured by information related to the cuff and/or measurement site; the information related to the cuff is information on type of the cuff; a specifying means for specifying to correct the blood pressure calculation parameter for each type of the cuff or each of the measurement site by the correction means is provided; and the specifying means is configured by a selection button for permitting selection of the type of cuff and/or the measurement site.

The information related to the cuff includes information of type of cuff, size, and the like.

According to one or more embodiments of the present invention, the optimum blood pressure calculation parameter can be set for every cuff and/or measurement site of the user and the measurement error can be reduced.

Further, according to one or more embodiments of the invention, the attachment condition information is configured by information related to the cuff and/or measurement site; the information related to the cuff is information on type of cuff; a specifying means for specifying to correct the blood pressure calculation parameter for every type of cuff or every measurement site by the correction means is arranged; and the specifying means is configured to determine the type of cuff and/or the measurement site based on a pressurization rate detected at the time of cuff pressurization.

Further, according to one or more embodiments of the invention, a display means for displaying the attachment condition information applied when the correction means corrects the blood pressure calculation parameter.

According to one or more embodiments of the present invention, there is provided a blood pressure measurement method of adjusting pressure to apply on a cuff when the cuff is attached to a blood pressure measurement site with a pressurization and depressurization means, and calculating a blood pressure value with a blood pressure calculation means based on a cuff pressure detected by a pressure detection means; the blood pressure measurement method including the steps of acquiring attachment condition information of the cuff by an information acquiring means; and correcting by a correction means a blood pressure value calculated by the blood pressure calculation means based on correction information; wherein the step of correcting by the correction means includes correcting a blood pressure calculation parameter based on the attachment condition information when the attachment condition information is acquired as the correction information; and the attachment condition information is user information input for specifying user indicating properties different from a general adult.

According to one or more embodiments of the present invention, the process of setting the optimum blood pressure calculation parameter for every attachment condition according to the attachment condition information and reducing the measurement error can be executed.

According to one or more embodiments of the present invention, the user information is configured by at least one of information such as a child or a pregnant woman, age, and birth date.

According to one or more embodiments of the present invention, the electronic sphygmomanometer and the blood pressure measuring method for accurately acquiring the blood pressure value using the acquired data are provided, so that the satisfaction level of the user can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of an electronic sphygmomanometer according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a blood pressure measurement operation according to the first embodiment of the present invention.

FIG. 3 is a table showing ratios for determining blood pressure calculation parameters for every age.

FIG. 4 is a view showing a display example in a display unit according to one or more embodiments of the present invention.

FIG. 5 is a flowchart showing another example of the blood pressure measurement operation according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing another example of the blood pressure measurement operation according to the first embodiment of the present invention.

FIG. 7 is a table showing the ratios for determining the blood pressure calculation parameters for general, pregnant women, and children.

FIG. 8 is a view showing a display example on the display unit according to one or more embodiments of the present invention.

FIG. 9 is a block diagram showing an example of a configuration of an electronic sphygmomanometer according to a second embodiment of the present invention.

FIG. 10 is a flowchart showing an example of a blood pressure measurement operation according to the second embodiment of the present invention.

FIG. 11 is a graph showing the blood pressure calculation algorithm (by cuffs) of the oscillometric type sphygmomanometer.

FIG. 12 is a view showing a display example on the display unit according to one or more embodiments of the present invention.

FIG. 13 is a view showing a display example on the display unit according to one or more embodiments of the present invention.

FIG. 14 is a block diagram showing another example of the configuration of the electronic sphygmomanometer according to the second embodiment of the present invention.

FIG. 15 is a flowchart showing another example of a blood pressure measurement operation according to the second embodiment of the present invention.

FIG. 16 is a view showing a display example on the display unit according to one or more embodiments of the present invention.

FIG. 17 is a graph showing a blood pressure calculation algorithm (by measurement sites) of the oscillometric type sphygmomanometer according to one or more embodiments of the present invention.

FIG. 18 is a graph showing an example of a blood pressure calculation algorithm of the oscillometric type sphygmomanometer according to one or more embodiments of the present invention.

DETAILED DESCRIPTION OF INVENTION

Embodiments of the present invention will be hereinafter described along with the drawings.

First Embodiment

First, an electronic sphygmomanometer according to a first embodiment of the present invention in which the user information input before the start of the blood pressure measurement is acquired as attachment condition information of the cuff, and then an optimum blood pressure calculation parameter is set based on the input user information to reduce the measurement error will be described.

As shown in FIG. 1, an electronic sphygmomanometer 2200 according to a first embodiment of the present invention includes a cuff 2101, an air tube 2102, a pressure sensor 2103, a pump 2104, a valve 2105, an oscillation circuit 2111, a pump drive circuit 2112, a valve drive circuit 2113, a timing unit 2115, a power supply 2116, a CPU 2120, a display unit 2121, a memory (for processing) 2122, a memory (for recording) 2123, an operation unit 2130, an interface 2171, and an external memory 2172.

FIG. 1 is a block diagram showing a configuration of the electronic sphygmomanometer 2200 according to the first embodiment of the present invention.

The cuff 2101 is a band shaped member that is connected to the air tube 2102 and that is attached to a blood pressure measurement site of the user to pressurize by air pressure.

The pressure sensor 2103 is an electrostatic capacitance type pressure sensor, in which a capacitance value changes according to the pressure in the cuff (cuff pressure).

The pump 2104 and the valve 2105 apply pressure to the cuff and adjust (control) the pressure in the cuff.

The oscillation circuit 2111 outputs a signal of the frequency corresponding to the capacitance value of the pressure sensor 2103.

The pump drive circuit 2112 and the valve drive circuit 2113 drive the pump 2104 and the valve 2105, respectively.

The timing unit 2115 is a device for timing the current date and time, and transmitting the timed date and time to the CPU 2120 as necessary.

The power supply 2116 supplies power to each configuring unit.

The CPU 2120 executes the control of the pump 2104, the valve 2105, the display unit 2121, the memories 2122, 2123, the operation unit 2130, and the interface 2171, the blood pressure determination process and the management of the recording values.

The display unit 2121 is configured by a display device such as a liquid crystal screen, and displays the blood pressure value and the user information, to be described later, according to a signal transmitted from the CPU 2120.

The memory (for processing) 2122 stores a ratio (to be described later) for determining blood pressure calculation parameter and a control program of the sphygmomanometer.

The memory (for recording) 2123 stores the blood pressure value, and stores the date and time, the user, and the measurement values in association to each other as necessary.

The operation unit 2230 is configured by a power supply switch 2131, a measurement switch 2132, a stop switch 2133, a record call out switch 2141, and a user selection switch 2242, and a user information input switch 2243, permits the operation input such as power ON/OFF of the sphygmomanometer and start of the measurement, and transmits the input signal to the CPU 2120.

Among such switches, the user information input switch 2243 is a switch for inputting the user information for specifying that the user demonstrates properties different from a general adult such as age, birth date, children or pregnant women. According to such configuration, the information of the user (user information) to whom the cuff 2101 is to be attached can be acquired as the attachment condition information of the cuff 2101 according to one or more embodiments of the present invention.

The interface 2171 records/reads out the blood pressure to and from the external memory 2171 according to the control of the CPU 2120.

The operation of inputting age as the user information, for example, and carrying out the blood pressure measurement using the electronic sphygmomanometer 2200 configured as above will be described according to the flowchart of FIG. 2.

FIG. 2 is a flowchart showing an example of a blood pressure measurement operation according to the first embodiment of the present invention.

First, when the power supply is turned ON by the operation of the power supply switch 2131 (step S2201), the CPU 2120 executes an initialization process of the memory (for processing) 2122 of the sphygmomanometer and performs a 0 mmHg adjustment of the pressure sensor 2103 (step S2202).

When the initialization process is finished, and the age of the user whose blood pressure is to be measured is input (step S2203), the CPU 2120 determines a blood pressure calculation parameter suited for the user of such age through an optimization process of the blood pressure calculation parameter, to be described later (step S2204).

The cuff 2101 is then wrapped around the measurement site of the user, and the measurement switch 2132 is pushed (step S2205), so that the CPU 2120 pressurizes the cuff pressure up to a predetermined pressure by the pump 2104 (step S2206 to step S2207), and gradually depressurizes the cuff pressure by the valve 2105 (step S2208).

The CPU 2120 extracts a pressure change component involved in the volume change of the artery superimposed on the cuff pressure obtained during depressurization, and calculates a blood pressure value by a predetermined calculation using the optimized blood pressure calculation parameter (step S2209).

After calculating the blood pressure value (step S2210: YES), the CPU 2120 opens the valve 2105 and exhausts the air of the cuff.

The CPU 2120 displays the calculated blood pressure value, the age information of the user, and the like on the display unit 2121 (step S2211), and records the same in the memory (for recording) 2123 in association with the measurement date and time/user (step S2212).

In step S2204, the optimization process of the blood pressure calculation parameter is carried out in the following manner. A table in which ratios α, β for determining blood pressure calculation parameters are classified by age as shown in FIG. 3 is recorded in the memory (for processing) 2122, so that the ratios α, β corresponding to the input age are determined based on the table of FIG. 3, and the blood pressure calculation parameters obtained by multiplying the ratios α, β by the maximum value of the pressure pulse wave amplitude are determined as the optimized blood pressure calculation parameters.

According to one or more embodiments of the present invention, the age is divided into a plurality of (e.g., four) age sections by a predetermined range, and the ratio α for determining systolic blood pressure calculation parameter and the ratio β for determining diastolic blood pressure calculation parameter are set in advance for every age section.

For the ratio α, the age section of 13 or older and younger than 18 is the largest or is 55%, and the ratio α becomes smaller as the age becomes older or younger of the relevant age section. For instance, the ratio α is the smallest or 45% when younger than 6 years old.

For the ratio β, the age section of 13 or older and younger than 18 is the smallest or is 60%, and the ratio β becomes greater as the age becomes older or younger of the relevant age section. For instance, the ratio β is the largest or 80% when younger than 6 years old.

In step S2211, a display as shown in FIG. 4 is made on the display unit 2121. The display unit 2121 is set with a blood pressure display portion 2121 a, an age display portion 2121 b, and a date and time display portion 2121 c. The calculated blood pressure value is displayed in the blood pressure display portion 2121 a, the age information of the user input in step S2203 is displayed in the age display portion 2121 b, and the current date and time timed by the timing unit 2115 is displayed in the date and time display portion 2121 c.

In the age display portion 2121 b, a list is displayed according to the age section set in the table of FIG. 3. An input result display portion M1 (a black triangular mark in the figure) is displayed at the side of the display site of the section to which the age input in step S2203 belongs, so that which section the input age, that is, the age applied when setting the blood pressure calculation parameter in step S2204 belongs to can be indicated. In FIG. 4, the input result display portion M1 is displayed at the side of the age section of 18 years old or older, which indicates that the age of 18 years old or older is input in step S2203.

However, the display method of the age display portion 2121 b is not necessarily limited thereto, and, for instance, only the section to which the age input in step S2203 belongs may be displayed.

An example of measuring the blood pressure value using the birth date for the user information will now be described according to the flowchart of FIG. 5 as another example of the blood pressure measurement operation according to the first embodiment.

FIG. 5 is a flowchart showing another example of the blood pressure measurement operation according to the first embodiment of the present invention.

First, similar to the blood pressure measurement operation described using FIG. 2, when the power supply is turned ON by the operation of the power supply switch 2131 (step S2221), the 0 mmHg adjustment of the pressure sensor 2103 is carried out (step S2222).

When the initialization process is finished, the user is selected (step S2223), and the birth date is input (step S2225) if the birth date is not input (step S2224: not input), the CPU 2120 calculates the age of the user from the current date and time timed by the timing unit 2115 based thereon (step S2226).

If the birth date is already input as the user information (step S2224: input), the CPU 2120 calculates the age of the user based on the data of the input birth date (step S2226).

The CPU 2120 then determines, based on the calculated age, the blood pressure calculation parameter optimum for the user of the relevant age by the optimization process of the blood pressure calculation parameter described above (step S2227).

In the processes after the following step S2228, the blood pressure measurement process is carried out using the optimized blood pressure calculation parameter, but processes are similar to the processes after step S2205 in FIG. 2 other than that the age calculated in step S2226 is displayed on the display unit 2121 in step S2234, and thus, the description thereof will be omitted.

An example of measuring the blood pressure value using the characteristic information such as a child and a pregnant woman for the user information will now be described according to the flowchart of FIG. 6 as another example of the blood pressure measurement operation according to the first embodiment.

FIG. 6 is a flowchart showing another example of the blood pressure measurement operation according to the first embodiment of the present invention.

First, similar to the blood pressure measurement operation described using FIG. 2, when the power supply is turned ON by the operation of the power supply switch 2131 (step S2261), the 0 mmHg adjustment of the pressure sensor 2103 is carried out (step S2262).

When the initialization process is finished, the user is selected (step S2263), and the characteristic information (child, pregnant woman, etc.) of the user is not input or changed (step S2264: not input or changed), the characteristic information of the user is input by the user information input switch 2243 (step S2265).

If the characteristic information (child, pregnant woman, etc.) of the user is input (step S2264: input), the CPU 2120 executes the subsequent processes based on the input information of the user.

In either case, the CPU 2120 determines, based on the input specified information of the user, the optimum blood pressure calculation parameter for the user by the optimization process of the blood pressure calculation parameter to be described later (step S2266).

In the processes after the following step S2267, the blood pressure measurement process is carried out using the optimized blood pressure calculation parameter, but processes are similar to the processes after step S2206 in FIG. 2 other than the process of step S2272, and thus, the description of each step excluding the process of step S2272 will be omitted.

In step S2266, the CPU 2120 carries out the optimization process of the blood pressure calculation parameter in the following manner. A table in which the ratios α, β for determining the blood pressure calculation parameters are classified for every characteristic information of the user, that is, for general, pregnant women, and children as shown in FIG. 7 is recorded in the memory (for processing) 2122, and the CPU 2120 determines the ratios α, β corresponding to the characteristic information of the user based on the table of FIG. 7, and determines the blood pressure calculation parameters obtained by multiplying the ratios α, β to the maximum value of the pressure pulse wave amplitude as the optimized blood pressure calculation parameter.

According to one or more embodiments of the present invention, the properties of the user are divided into a total of three; pregnant women, children, and general excluding pregnant women and children, where the ratio α for determining the systolic blood pressure calculation parameter and ratio β for determining the diastolic blood pressure calculation parameter are set in advance for each property section.

The ratio α is the largest or 55% for pregnant women and the smallest or 45% for children.

The ratio β is the smallest or 60% for pregnant women and the largest or 80% for children.

In step S2272 of the flowchart in FIG. 6, a display as shown in FIG. 8 is made on the display unit 2121. A user property display portion 2121 d is set on the display unit 2121 in place of the age display portion 2121 b shown in FIG. 4, and the user characteristic information input in step S2263 is displayed on the user property display portion 2121 d.

Here, in the user property display portion 2121 d, a list is displayed according to the section of the user property set in the table of FIG. 7. An input result display portion M2 similar to FIG. 4 is displayed at the side of the display site of the user property input in step S2263, so that what the input user property is, that is, the user property applied when setting the blood pressure calculation parameter in step S2266 can be indicated. In FIG. 8, the input result display portion M2 is displayed at the side of the “general” other than pregnant women and children, which indicates that the “general” is input in step S2266.

However, the display method of the user property display portion 2121 d is not necessarily limited thereto, and only the user property input in step S2263 may be displayed.

The characteristic information of the user may use information recorded in an external recording medium (external memory 2172 such as USB memory) or a personal computer, or a server through the Internet.

The recording value may use a value recorded in an external recording medium (external memory 2172 such as USB memory) or a personal computer, or a server via the Internet.

As described with the case in which “input” is selected in step S2264 in FIG. 6, the characteristic information of the user may be that which is input in the past blood pressure measurement and recorded in the memory (recording unit) 2123, and such user information may be called out for use.

In this case, the user information may be input only when the information of the user is not input or is changed as described with the case in which “not input or changed” is selected in step S2264.

As described above, there is provided an electronic sphygmomanometer 2200 including a biological information acquiring means for measuring a blood pressure value, a recording means (memory 2123) for recording the blood pressure value, a means (memory 2122) for storing a ratio for determining a blood pressure calculation parameter and control program of the sphygmomanometer, an operation means (operation unit 2230) for performing operations such as blood pressure measurement, a correction means (CPU 2120) for correcting biological information acquired by the biological information acquiring means based on separately acquired correction information, and an output means (display unit 2121) for outputting corrected information (blood pressure value) after the correction, the biological information acquiring means including a cuff 2101 to be attached to a blood pressure measurement site, pressurization and depressurization means 2104, 2105 for adjusting a pressure to apply on the cuff 2101, a pressure detection means (pressure sensor 2103) for detecting a pressure in the cuff, and a blood pressure calculation means (CPU 2120) for calculating the blood pressure value from the cuff pressure; the electronic sphygmomanometer further including an information acquiring means (CPU 2120 that executes steps S2203, S2226, S2264, S2265) for acquiring user information (attachment condition information of the cuff 2101) input before start of the blood pressure measurement as the correction information, wherein the correction means (CPU 2120 that executes steps S2204, S2227, S2266) is adapted to correct the blood pressure calculation parameter based on the user information (attachment condition information of the cuff 2101).

According to the above described configuration, the optimum blood pressure calculation parameter is set for every user according to the information of the user such as the characteristic information of whether a child or a pregnant woman, the age, and the birth date even if the information has different properties for every user (attachment condition of the cuff 2101), so that the measurement error can be reduced.

If the user information (attachment condition information of the cuff 2101) is not appropriately input in steps S2203, S2225, S2265, the blood pressure calculation parameter is not appropriately determined in steps S2204, S2227, S2266. Therefore, according to one or more embodiments of the present invention, the user can check whether or not the user information is appropriately input by displaying the user information (attachment condition information of the cuff 2101) input before the start of the blood pressure measurement, that is, the user information applied when setting the blood pressure calculation parameter in steps S2204, S2227, S2266 on the display means (display unit 2121), where the necessity to redo the blood pressure measurement can be easily recognized based on the display of the display unit 2121 if the input user information is not appropriate. Thus, the user is able to know the accurate blood pressure value.

Second Embodiment

An electronic sphygmomanometer according to the second embodiment of the present invention in which the information related to the cuff or/and the measurement site of the user that is input is acquired as the attachment condition information of the cuff, and the optimum blood pressure calculation parameter is set based on the information related to the cuff and/or the measurement site of the user that is input to reduce measurement error will be described below.

FIG. 9 is a block diagram showing an electronic sphygmomanometer 2300 for setting the blood pressure calculation parameter based on the type of selected cuff and calculating the blood pressure of the electronic sphygmomanometer 2300 according to the second embodiment of the present invention, where the same reference numerals are denoted for the configurations similar to the configurations according to the first embodiment, and thus, the description thereof will be omitted.

The cuff 2101 includes three cuffs, a cuff 2101A, a cuff 2101B, and a cuff 2101C according to the type. The user selects the cuff of a size appropriate for the peripheral length etc. of his/her measurement site from the cuff 2101A, the cuff 2101B, and the cuff 2101C, and connects such cuff to an air tube 2102 to carry out blood pressure measurement.

The display unit 2321 is configured by a display device such as a liquid crystal screen, and displays the blood pressure value and the cuff type information, to be described later, according to the signal transmitted from the CPU 2120.

In addition to the power supply switch 2131, the measurement switch 2132, the stop switch 2133, and the record call out switch, an operation unit 2330 also includes a cuff selection switch 2341.

The cuff selection switch 2341 is a selection button that permits the selection of the type of cuff 2101, that is, which one of the cuff 2101A, the cuff 2101B, and the cuff 2101C is used to perform the blood pressure measurement. According to such configuration, the information related to the cuff 2101 can be acquired as the attachment condition information of the cuff 2101 according to one or more embodiments of the present invention.

The algorithm tables A, B, C are memories recorded with a table in which the optimum blood pressure calculation parameter is classified for every type of cuff 2101, where the algorithm tables A, B, C 2351 may be configured to include the memories 2122, 2123.

Although not shown in FIG. 9, the electronic sphygmomanometer 2300 may appropriately include an interface 2171, an external memory 2172, and a user selection switch 2242, as shown in FIG. 1.

The blood pressure measurement operation using the electronic sphygmomanometer configured as above will be described according to the flowchart in FIG. 10.

FIG. 10 is a flowchart showing an example of the blood pressure measurement operation according to the second embodiment of the present invention.

First, when the power supply is turned ON by the operation of the power supply switch 2131 (step S2301), the CPU 2120 performs the 0 mmHg adjustment of the pressure sensor 2103 (step S2302).

When the initialization process is finished, the type information of the cuff same as the type of the wrapped cuff 2101 is input (selected) by the cuff selection switch 2341 (step S2303). The CPU 2120 determines a blood pressure calculation parameter suited for the specification of the user through an optimization process of the blood pressure calculation parameter, to be described later, based on the input type information of the cuff (step S2304).

In the processes after the following step S2305, the blood pressure measurement process is carried out using the optimized blood pressure calculation parameter, but processes are similar to the processes after step S2205 in FIG. 2 other than the process of step S2311, and thus, the description of each step excluding the process of step S2311 will be omitted.

In step S2304, the optimization process of the blood pressure calculation parameter is carried out in the following manner.

For instance, focusing on two types of cuffs, the cuff 2101A and the cuff 2101B, the cuff 2101A and the cuff 2101B show different properties in relationship between the cuff pressure and the pressure pulse wave amplitude, as shown in FIG. 11. Furthermore, the cuffs also show different properties with respect to the blood pressure calculation parameter obtained by multiplying a predetermined ratio to the maximum value of the pressure pulse wave amplitude, and hence, the CPU 2120 determines the respective blood pressure calculation parameter (value obtained by multiplying a predetermined ratio with respect to the maximum value of the pressure pulse wave amplitude) of the cuff 2101A and the cuff 2101B as the optimum parameter based on FIG. 11.

In other words, when the type of the cuff 2101 is selected in such a manner, the CPU 2120 can determine the optimum blood pressure calculation parameter for every type of cuff 2101 using the table recorded in the algorithm tables A, B, C.

According to one or more embodiments of the present invention, the maximum value of the pressure pulse wave amplitude and the systolic blood pressure calculation parameter as well as the diastolic blood pressure calculation parameter are all set so as to be greater for the cuff 2101A in the cuff 2101A and the cuff 2101B by way of example.

In step S2311 of the flowchart of FIG. 10, a display shown in FIG. 12 is made on the display unit 2321, where the display unit 2321 is set with a blood pressure display portion 2321 a, a cuff type display portion 2321 b, and a date and time display portion 2321 c. The calculated blood pressure value is displayed in the blood pressure display portion 2321 a, the information on the type of cuff 2101 input in step S2303 is displayed in the cuff type display portion 2321 b, and the current date and time timed by the timing unit 2115 is displayed in the date and time display portion 2321 c.

A list of types of cuff 2101 is displayed on the cuff type display portion 2321 b. An input result display portion M3 similar to FIG. 4 is displayed at the side of the display site of the type of the cuff 2101 input in step S2303, so that what the input type is, that is, the type applied when setting the blood pressure calculation parameter in step S2304 can be indicated. In FIG. 12, the input result display portion M3 is displayed at the side of the cuff A, which indicates that the cuff A is input in step S2303.

However, the display method of the cuff type display portion 2321 b is not necessarily limited thereto, and only the type input in step S2303 may be displayed.

The blood pressure calculation parameter is not limited to being set according to the type of cuff 2101, as described above, and the blood pressure calculation parameter may be set according to the size or the like of the cuff 2101.

When setting the blood pressure calculation parameter according to the size of the cuff 2101, a cuff size display portion 2321 d is set as in the display unit 2321 shown in FIG. 13 in place of the cuff type display portion 2321 b, and the cuff size information is displayed thereon.

A list of sizes of the cuff 2101 is displayed on the cuff size display portion 2321 d. An input result display portion M4 similar to FIG. 4 is displayed at the side of the display site of the size input with a predetermined input means (input switch), so that what the input size is, that is, the size applied when setting the blood pressure calculation parameter, can be indicated. In FIG. 13, the input result display portion M4 is displayed at the side of the largest L size for the size of the cuff 2101, which indicates that L size is input.

However, the display method of the cuff size display portion 2321 d is not necessarily limited thereto, and only the input size may be displayed.

An example using an electronic sphygmomanometer in which the blood pressure calculation parameter is set based on the measurement site of the selected user, and the blood pressure value is measured of the electronic sphygmomanometer 2301 according to the second embodiment of the present invention will now be described. This will be specifically described below with the drawings.

The configuration similar to the embodiments described above of the configuration of the electronic sphygmomanometer is denoted with the same reference numerals, and, thus, the description thereof will be omitted.

The configuration of the electronic sphygmomanometer 2301 is configured with the configuration shown in FIG. 14.

FIG. 14 is a block diagram showing the configuration of the electronic sphygmomanometer 2301.

The display unit 2361 is configured by the display device such as the liquid crystal screen, and displays the blood pressure value, and the measurement site information, to be described later, according to the signal transmitted from the CPU 2120.

The operation unit 2330 includes a measurement site selection switch 2342 in place of the cuff selection switch 2341 shown in FIG. 9. According to such configuration, the information related to the measurement site where the cuff 2101 is attached can be acquired as the attachment condition information of the cuff 2101 according to one or more embodiments of the present invention.

Furthermore, the algorithm tables A, B, C 2352 are configured with a memory where a table in which the optimum blood pressure calculation parameter is classified for every measurement site.

The blood pressure measurement operation using the electronic sphygmomanometer 2301 configured as above will be described according to the flowchart of FIG. 15.

FIG. 15 is a flowchart showing an example of the blood pressure measurement operation according to the second embodiment of the present invention.

First, when the power supply is turned ON by the operation of the power supply switch 2131 (step S2321), the CPU 2120 performs the 0 mmHg adjustment of the pressure sensor 2103 (step S2322), similar to the blood pressure measurement operation described using FIG. 2.

When the initialization process is finished, the measurement site same as the wrapped measurement site is input (selected) by the measurement site selection switch 2342 (step S2323). The CPU 2120 determines a blood pressure calculation parameter suited for the specification of the user through an optimization process of the blood pressure calculation parameter, to be described later, based on the input measurement site information of the cuff (step S2324).

In the processes after the following step S2325, the blood pressure measurement process is carried out using the optimized blood pressure calculation parameter, but processes are similar to the processes after step S2205 in FIG. 2 other than the process of step S2331, and thus, the description of each step excluding the process of step S2331 will be omitted.

In step S2324 described above, the optimization process of the blood pressure calculation parameter is carried out in the following manner.

If the measurement site differs as with the upper arm and the wrist, the upper arm and the wrist show different properties as in FIG. 17 showing the relationship between the cuff pressure and the pressure pulse wave amplitude, similar to the above described case focusing on the type of cuff 2101.

Therefore, if the measurement site differs, the CPU 2120 can determine the blood pressure calculation parameter as the blood pressure calculation parameter optimized at each measurement site according to the same procedure as the above described case focusing on the type of cuff 2101 using FIG. 17.

According to one or more embodiments of the present invention, the upper arm and the wrist of the measurement sites will be described by way of example, where the maximum value of the pressure pulse wave amplitude and the systolic blood pressure calculation parameter are set to be greater in the wrist, while the diastolic blood pressure calculation parameter is set to be greater in the upper arm.

In step S2331 of the flowchart of FIG. 15, the display shown in FIG. 16 is made on the display unit 2361, where a blood pressure display portion 2361 a, a measurement site display portion 2361 b, and a date and time display portion 2361 c are set in the display unit 2361. The calculated blood pressure value is displayed in the blood pressure display portion 2322 a, the measurement site information input in step S2323 is displayed on the measurement site display portion 2316 b, and the current date and time timed by the timing unit 2115 is displayed on the date and time display portion 2361 c.

A list of measurement sites is displayed on the measurement site display portion 2361 b. An input result display portion M5 similar to FIG. 4 is displayed at the side of the display site of the measurement site input with a measurement site selection switch 2342, so that what the input measurement site is, that is, the measurement site information applied when setting the blood pressure calculation parameter in step S2324, can be indicated. In FIG. 16, the input result display portion M5 is displayed at the side of the “upper arm”, which indicates that “upper arm” is input in step S2323.

However, the display method of the measurement site display portion 2361 b is not necessarily limited thereto, and only the input measurement site information may be displayed.

Although not shown, the electronic sphygmomanometer 2301 according to the second embodiment of the present invention may be configured to permit to select the measurement with arbitrary measurement information for every measurement site and cuff 2101, set an optimum blood pressure calculation parameter by switching to an algorithm corresponding to the selected measurement information, and measure the sphygmomanometer as a configuration different from the configuration described above.

When adopting such a configuration, the CPU 2120 can execute not only the process of “input (select) using cuff”, but also the process of “input (select) measurement site and cuff” in step S2303 in FIG. 10, and thus, the a plurality of cuffs 2101 and the measurement information corresponding to the measurement site can be selected to carry out the blood pressure measurement with one apparatus.

Although not shown, the electronic sphygmomanometer 2301 according to the second embodiment of the present invention may be configured to decide on the type of cuff 2101 or the measurement site based on the pressurization speed detected at the time of cuff pressurization, and carry out the blood pressure measurement with a corresponding appropriate blood pressure calculation parameter for every decided type of cuff 2101 or measurement site as a configuration different from the configuration described above, and is not limited to being configured to specify the type of cuff 2101 or the measurement site with the selection button (cuff selection switch 2341, measurement site selection switch 2342) as described above.

As described above, there are provided electronic sphygmomanometers 2300, 2301 including a biological information acquiring means for measuring a blood pressure value, a recording means (memory 2122, 2123) for recording the blood pressure value, an operation means (operation unit 2330) for performing operations such as blood pressure measurement, a correction means (CPU 2120) for correcting the biological information acquired by the biological information acquiring means based on the separately acquired correction information, and an output means (display unit 2321, 3261) for outputting the corrected information (blood pressure value) after the correction, the biological information acquiring means being configured by a cuff 2101 (2101A, 2101B, 2101C) to be attached to a blood pressure measurement site, a pressurization and depressurization means 2104, 2105 for adjusting the pressure to apply on the cuff 2101, a pressure detection means (pressure sensor 2103) for detecting the pressure of the cuff, and a blood pressure calculation means (CPU 2120) for calculating the blood pressure value from the cuff pressure, the electronic sphygmomanometer further including an information acquiring means (CPU 2120 that executes steps S2303, 2323) for acquiring the information (attachment condition information of the cuff 2101) related to the cuff 2101 and/or measurement site as the correction information, wherein the correction means (CPU 2120 that executes steps S2304, 2324) corrects the blood pressure calculation parameter based on the information (attachment condition information of the cuff 2101) related to the cuff 2101 and/or the measurement site.

According to such configuration, an effect in that the measurement error can be reduced even when the cuff size, the type, or the measurement site is changed is obtained because the blood pressure is measured with the optimum blood pressure calculation parameter set for every user cuff and/or measurement site (attachment condition of the cuff 2101).

As described above, the electronic sphygmomanometer 2301 according to the second embodiment of the present invention may include a specifying means for specifying to correct the blood pressure calculation parameter for every type of cuff or measurement site by the correction means, the specifying means being configured with a selection button (cuff selection switch 2341, measurement site selection switch 2342) for permitting the selection of the type of cuff and/or the measurement site.

The blood pressure calculation parameter is not appropriately determined in steps S2304, S2324 unless the information (attachment condition information of the cuff 2101) related to the cuff 2101 and/or the measurement site is appropriately input in steps S2303, S2322. Therefore, the information (attachment condition information of the cuff 2101) related to the cuff 2101 and/or the measurement site, that is, the information related to the cuff 2101 and/or the measurement site applied when setting the blood pressure calculation parameter in steps S2304, S2324 is displayed on the display means (display unit 2321, 2361) as in the present example, so that the user can check whether or not the information is appropriately input, and can easily recognize the necessity to redo the blood pressure measurement based on the display of the display unit 2321, 2361 if the input information is not appropriate. Thus, the user is able to know the correct blood pressure value.

Embodiments of the present invention are not limited only to the configuration of the above-described embodiments, and a great number of embodiments can be realized.

For example, the electronic sphygmomanometer 2200, 2300, 2301 may be configured to download an appropriate parameter, threshold value, algorithm, or the like from a dedicated server to expand the function. In this case, the version of the software may be upgraded with the hardware as is, or optimization can be easily realized by the user.

The function expansion of the electronic sphygmomanometer 2200, 2300, 2301 may be executed from a user terminal such as a personal computer possessed by the user without using the server. In this case, the parameter, the threshold value, the algorithm, and the like may be downloaded from a recording medium such as a CD-ROM.

The electronic sphygmomanometer 2200, 2300, 2301 may be directly and communicably connected wirelessly or by wire to other biological information acquiring device such as a body composition meter, a pedometer, or an electronic thermometer. In this case as well, data may be mutually transmitted and received to enhance the individual accuracy.

Embodiments of the present invention can be used in an electronic sphygmomanometer adopting an oscillometric method that uses a cuff.

While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

DESCRIPTION OF REFERENCE NUMERALS

-   2200, 2300, 2301 electronic sphygmomanometer -   2101 cuff -   2101A cuff (A) -   2101B cuff (B) -   2101C cuff (C) -   2103 pressure sensor -   2104 pump -   2105 valve -   2115 timing unit -   2120 CPU -   2121, 2321, 2361 display unit -   2122 memory (for processing) -   2123 memory (for recording) -   2230, 2330 operation unit -   2141 record call out switch -   2242 user selection switch -   2243 user information input switch -   2341 cuff selection switch -   2342 measurement site selection switch -   2351, 2352 algorithm table A, B, C 

1. An electronic sphygmomanometer comprising: a cuff to be attached to a blood pressure measurement site; a pressurization and depressurization means for adjusting a pressure to apply to the cuff; a pressure detection means for detecting the pressure of the cuff; a blood pressure calculation means for calculating a blood pressure value from the cuff pressure; a recording means for recording the blood pressure value; an operation means for carrying out a blood pressure measurement; a correction means for correcting a blood pressure value calculated by the blood pressure calculation means based on a separately acquired correction information; and an information acquiring means for acquiring an attachment condition information of the cuff as the correction information, wherein when the attachment condition information is acquired as the correction information by the information acquiring means, the correction means corrects a blood pressure calculation parameter based on the attachment condition information, and wherein the attachment condition information is a user information input that specifies a user indicating properties different from a general adult.
 2. The electronic sphygmomanometer according to claim 1, wherein the user information is configured by at least one of information selected from the group consisting of a child, a pregnant woman, an age, and a birth date.
 3. The electronic sphygmomanometer according to claim 1, wherein the attachment condition information is configured by information related to the cuff and/or measurement site, wherein the information related to the cuff is information on a type of cuff, wherein a specifying means for specifying to correct the blood pressure calculation parameter for every type of cuff or every measurement site by the correction means is arranged, and wherein the specifying means is configured by a selection button that permits a selection of the type of cuff and/or the measurement site.
 4. The electronic sphygmomanometer according to claim 1, wherein the attachment condition information is configured by information related to the cuff and/or measurement site, wherein the information related to the cuff is information on a type of cuff, wherein a specifying means for specifying to correct the blood pressure calculation parameter for every type of cuff or every measurement site by the correction means is arranged, and wherein the specifying means determines the type of cuff and/or the measurement site based on a pressurization rate detected at a time of cuff pressurization.
 5. The electronic sphygmomanometer according to claim 1, further comprising: a display means for displaying the attachment condition information applied when the correction means corrects the blood pressure calculation parameter.
 6. A blood pressure measurement method of adjusting a pressure to apply on a cuff when the cuff is attached to a blood pressure measurement site with a pressurization and depressurization means, and calculating a blood pressure value with a blood pressure calculation means based on a cuff pressure detected by a pressure detection means, the blood pressure measurement method comprising the steps of: acquiring an attachment condition information of the cuff by an information acquiring means, and correcting by a correction means a blood pressure value calculated by the blood pressure calculation means based on correction information, wherein the step of correcting by the correction means comprises correcting a blood pressure calculation parameter based on the attachment condition information when the attachment condition information is acquired as the correction information, and wherein the attachment condition information is a user information input for specifying a user indicating properties different from a general adult.
 7. The blood pressure measurement method according to claim 6, wherein the user information is configured by at least one of information such as a child or a pregnant woman, age, and birth date. 